961. Prevalence and Macrolide Resistance of Mycoplasma genitalium After Initiation of HIV Preexposure Prophylaxis

BACKGROUND: Recent evidence shows that patients using HIV preexposure prophylaxis (PrEP) have an increased rate of bacterial sexually transmitted infections (STIs), including syphilis, chlamydia, and gonorrhea. The rate of Mycoplasma genitalium infections and the susceptibility of M. genitalium in patients on PrEP have been less well described. METHODS: We studied all patients who started on PrEP in the AZ Sint-Jan Hospital Bruges from January 6, 2017 to January 4, 2019. Patients were screened for M. genitalium and other bacterial STIs with rectal swabs, pharyngeal swabs, first-voided urine and blood collections at baseline and quarterly intervals after initiating PrEP. TaqMan array card technology was used to detect M. genitalium and determine macrolide-resistance mediating mutations in the region V of the 23S rRNA gene (A2058G, A2059G, A2058C, and others). Patients with an STI were treated based on a national guideline. Proportions were estimated using a Generalized Estimating Equations model with independent correlation structure. RESULTS: A total of 136 males and 1 female (median age, 40 years (interquartile range (IQR), 20–79)) were included in the study. All men were gay or bisexual. The median follow-up time was 11.3 months (IQR, 4.7–15.3). In total, 117 patients (85%) used PrEP daily at their last visit. The estimated proportion of patients with M. genitalium at baseline, 3 months, 6 months, 9 months, and 12 months was 7% (95% CI 4–13), 12% (95% CI 7–20), 7% (95% CI 4–15), 6% (3–15), and 6% (2–15). Thirty-two patients (23%) tested at least once positive for M. genitalium during the study period. The estimated percentage of macrolide resistance increased from 40% (95% CI 16–70) at baseline to 71% (95% CI 44–89), 67% (95% CI 27–92), 80% (95% CI 31–97), and 75% (95% CI 24–97) at 3 months, 6 months, 9 months, and 12 months, respectively. CONCLUSION: After initiation of PrEP, the prevalence of M. genitalium in our cohort at quarterly screening was not increased compared with baseline. However, a nonsignificant trend of an increased percentage of macrolide-resistant strains was observed. DISCLOSURES: All Authors: No reported Disclosures.